Enables several functions, including ATP binding activity; phosphatidylinositol binding activity; and rhodopsin kinase activity. Involved in negative regulation of phospholipase C-activating phototransduction signaling pathway; phototransduction, visible light; and positive regulation of smoothened signaling pathway. Predicted to be located in cytoplasm and plasma membrane. Is expressed in adult head; head; organism; retina; and wing disc. Orthologous to human GRK2 (G protein-coupled receptor kinase 2) and GRK3 (G protein-coupled receptor kinase 3).